Structural assessment of masonry in ruinous state: typology, materials behaviour, non-destructive techniques and consolidation

The typology of masonry castles and fortresses in ruinous state often covers 3-leaf masonry. These walls demonstrate a large complexity, in layout and materials use (brick/stone masonry, mortar types used), in relation to their structural behaviour (different strength and stiffness of the paraments), and in the state of the masonry: heterogeneity or voids, cohesion in between leaves, degradation phenomena. Their failure modes are governed by loss of cohesion in between the different leaves. On site investigation techniques such as endoscopy or geo-electric measurements aim at gathering information of the actual state of the masonry. Grout injection is a possible option for consolidating the load-bearing capacity by means of filling voids and restoring cohesion. Two case studies are treated: the Maegdentoren at Zichem (Tower of Virgins), which is now, after partial collapse in 2006, partially in a ruinous state; and the Castle of Beersel, at which geo-electric measurements have been performed before and after consolidation by means of grout injection.status: publishe